LM1881 - Video Sync Separator IC

Pin Configuration

This is an output pin which provides the stripped out composite signal

2

Composite Video In (CVIN)

This is the input pin to which the video with composite is fed

3

Vertical Video Out (VSOUT)

This pin outputs the composite free filtered video signal

4

Ground (GND)

Connected to ground of the system

5

Burst/Back Out (BPOUT)

Outputs burst or back porch timing signal

6

Reset

Used to reset the IC

7

Odd/Even Output (OEOUT)

8

VCC

Powered normally with +5V or +12V

LM1881 Specifications

Operating Voltage: +5V to +12V

Can process Sync over composite, Sync over luma and composite sync videos

High Input resistance and low power supply drain current.

Scan Rate: 150kHz

LM1881 Equivalent

EL1881, EL4581

Alternatives Video sync separators

LM1981, EL1993, EL4583

Where to use the LM1881 Video Sync Separator IC

The LM1881 is used in many video related application where composite video and RGB video is involved. One noticeable main application of the IC is to convert sync over composite videos (HSYNC + VSYNC + CVBS) into CSYNC video (HSYNC+VSYNC) by removing the composite video (CVBS) aspects. This comes in handy while using the old RGB monitors since they do not support composite sync information.

So if you are looking for a composite video conversion IC then LM1881 might be of interest to you.

How to use LM1881 IC

One big advantage of LM1881 is that it can work with minimum number of components. Along with the IC, it only requires an additional resistor and a couple of capacitors. The typical connection diagram for LM1881 is shown below.

The LM1881N IC has an operating voltage from 5-12V, but normally it is operated either in +5V or +12V. The video with composite is fed to pin 2; the capacitor acts as a parasitic capacitor to filter noise. The output video which is free of composite and can be used on RGB monitors can be obtained from the pin 3.